The process or result of becoming covered with cobwebs, or the cobwebs themselves collectively.
From 'cobweb' with the gerund suffix '-ing'. This nominalizes the verb 'to cobweb,' allowing the concept of web-making to be treated as a noun describing the accumulation process.
In architecture and building preservation, conservators actually study 'cobwebbing patterns' to date when spaces were last cleaned or maintained—dust and spider activity leave traces that tell the history of a room!
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